Only congress can declare war. What the US is doing are clearly acts of war. But hey, you won’t have to fight it. So who cares, right?
The problem is, declaring war on another nuclear power isn’t a good idea.🙄
In the current war in Ukraine, the US is a cobelligerent, not a belligerent.
A Congressional declaration activates the treason clause, so that opposition to the war past a certain point or trading with the enemy becomes treason.
No one ever considered this to be a legal restriction on the President's use of the armed forces before Vietnam, but Presidents normally had to obtain Congressional action simply because US forces were too small for any substantial engagement. But they were freely used in many smaller engagements like Haiti, gunboats in China, Central America, etc., without Congressional authorization.